(CNN) -- Despite a broken radio navigation system, planes will still be able to land and depart from Manila airport, aviation officials in the Philippines said Saturday.

The system, especially important for planes landing at night, bogged down Saturday.

Earlier, it was thought that the Doppler VHF Omnidirectional Rangefinder's malfunction would affect the landing and departure of 136 planes if it's not repaired by sunset. A total of 155 international and domestic flights were scheduled to come in Saturday night, the Civil Aviation Authority said.

Several Philippine Airlines flights from the United States and the Middle East were delayed. The navigation system is key to aiding approaching and landing planes at Ninoy Aquino International Airport.

But radar and distance measuring equipment were operational and air traffic controllers would be able to guide planes until they closed in on the runway, said Alfonso Cusi, director general of the Civil Aviation Authority, in a news release. At that point, approaching planes would be able to land provided that visibility was good.

Another airport north of Manila was prepared to receive diverted flights, Cusi said.